import java.util.Scanner;

public class Exercise {
    public static void main (String[] args){
        Scanner sr = new Scanner(System.in);
        int n = sr.nextInt();
        if(n<2){
            System.out.println(n+"不是素数");
            return;
        }
        if(n==2){
            System.out.println(n+"是素数");
        }
        for (int i = 2; i < Math.sqrt(n); i++) {
            if(n%i==0){
                System.out.println(n+"不是素数");
                break;
            }else{
                System.out.println(n+"是素数");
            }
        }
    }

}
